1LDT

COMPLEX OF LEECH-DERIVED TRYPTASE INHIBITOR WITH PORCINE TRYPSIN

Summary for 1LDT

• Entry DOI: 10.2210/pdb1ldt/pdb
• Descriptor: TRYPSIN, TRYPTASE INHIBITOR, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: complex (hydrolase-inhibitor), hydrolase, inhibitor, inflammation, tryptase, complex (hydrolase-inhibitor) complex, complex (hydrolase/inhibitor)
• Biological source: Hirudo medicinalis (medicinal leech); More
• Cellular location: Secreted, extracellular space: P00761
• Total number of polymer chains: 2
• Total formula weight: 28284.19

Authors

Stubbs, M.T. (deposition date: 1997-05-15, release date: 1998-05-20, Last modification date: 2024-10-16)

Primary citation

Stubbs, M.T.,Morenweiser, R.,Sturzebecher, J.,Bauer, M.,Bode, W.,Huber, R.,Piechottka, G.P.,Matschiner, G.,Sommerhoff, C.P.,Fritz, H.,Auerswald, E.A.
The three-dimensional structure of recombinant leech-derived tryptase inhibitor in complex with trypsin. Implications for the structure of human mast cell tryptase and its inhibition.
J.Biol.Chem., 272:19931-19937, 1997

PubMed Abstract: The x-ray crystal structure of recombinant leech-derived tryptase inhibitor (rLDTI) has been solved to a resolution of 1.9 A in complex with porcine trypsin. The nonclassical Kazal-type inhibitor exhibits the same overall architecture as that observed in solution and in rhodniin. The complex reveals structural aspects of the mast cell proteinase tryptase. The conformation of the binding region of rLDTI suggests that tryptase has a restricted active site cleft. The basic amino terminus of rLDTI, apparently flexible from previous NMR measurements, approaches the 148-loop of trypsin. This loop has an acidic equivalent in tryptase, suggesting that the basic amino terminus could make favorable electrostatic interactions with the tryptase molecule. A series of rLDTI variants constructed to probe this hypothesis confirmed that the amino-terminal Lys-Lys sequence plays a role in inhibition of human lung tryptase but not of trypsin or chymotrypsin. The location of such an acidic surface patch is in accordance with the known low molecular weight inhibitors of tryptase.

PubMed: 9242660
DOI: 10.1074/jbc.272.32.19931

Experimental method

X-RAY DIFFRACTION (1.9 Å)